Implantable cardioverter-defibrillators (ICDs) are known in the art. Prior devices have included transvenous or epicardial devices. Transvenous devices include leads that reside in blood vessels extending to electrodes placed in the heart. Epicardial devices include electrodes placed on the outside of the heart, usually placed via invasive surgery. New developments in the field include subcutaneous-only systems which lack leads in the vasculature and/or electrodes in or on the heart. Methods and devices configured to respond to new challenges in the subcutaneous ICD space are desired.